1. Field of the Invention
The present invention relates to a charged particle beam drawing method and apparatus for drawing patterns on a workpiece mounted on a movable stage by a charged particle beam on the basis of a drawing data inputted to the charged particle beam drawing apparatus.
2. Description of Related Art
As is known in the prior art, a charged particle beam drawing apparatus draws patterns corresponding to figures included in a drawing data inputted to the charged particle beam drawing apparatus, on a workpiece mounted on a movable stage by a charged particle beam passed through an opening of a first forming aperture member and an opening of a second forming aperture member. For example, the charged particle beam drawing apparatus is described in Japanese Unexamined Patent Publication No. 2007-324229.
As described in Japanese Unexamined Patent Publication No. 2007-324229, the charged particle beam drawing apparatus includes a charged particle beam gun and a first forming aperture member having an opening. The charged particle beam emitted from the charged particle beam gun is passed through the opening of the first forming aperture member. The charged particle beam drawing apparatus further includes a second forming aperture member having an opening. The charged particle beam passed through the opening of the first forming aperture member is passed through the opening of the second forming aperture member. The charged particle beam drawing apparatus further includes a movable stage supporting a workpiece. Patterns corresponding to figures included in a drawing data are drawn on the workpiece by the charged particle beam passed through the opening of the second forming aperture member.
In the charged particle beam drawing apparatus as described in Japanese Unexamined Patent Publication No. 2007-324229, in order to cancel a position difference of the charged particle beam on the workpiece on the basis of a position in the opening of the second forming aperture where the charged particle beam is passed through, the charged particle beam is offset by a sub-deflector. Therefore, in the charged particle beam drawing apparatus as described in Japanese Unexamined Patent Publication No. 2007-324229, the size of a subfield is smaller than the size of a limit area. The limit area is where the charged particle beam can be maximally deflected by the sub-deflector without a distortion of the charged particle beam. Consequently, it is impossible for the charged particle beam drawing apparatus as described in Japanese Unexamined Patent Publication No. 2007-324229 to increase a throughput sufficiently.